Watercraft steering device and watercraft

Abstract

A watercraft steering device can include at least one of steerage status detection device configured to detect a steerage status following an operation of the steering wheel, running status detecting device configured to detect a running status of the watercraft, watercraft propulsion unit status recognition device configured to recognize a status of an outboard motor such as an installation number thereof, and electric motor status detection device configured to detect a status of an electric motor, and can further include a lower unit turning force characteristic computation device configured to compute a lower unit turning force characteristic based on a detection value from at least one of the device, and an ECU configured to control at least one of a reaction force to the steering wheel, a limit lower unit turning angle, and a propulsive force based on a computed lower unit turning force characteristic and / or selecting the electric actuator to operate.

Description

PRIORITY INFORMATION[0001]The present application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2006-312184, filed on Nov. 17, 2006, the entire contents of which are expressly incorporated by reference herein.BACKGROUND OF THE INVENTIONS[0002]1. Field of the Inventions[0003]The present inventions relate to watercraft steering systems, and more particularly, to such systems having an electric actuator which is actuated as an operator turns a steering member.[0004]2. Description of the Related Art[0005]Japanese Patent Document JP-A-2005-254848 discloses a steering system in which an electric actuator of the steering device is actuated as an operator operates the steering wheel. The watercraft is thus steered in response to the operation amount of the steering wheel.[0006]External forces on the watercraft are also detected. Based on the detected external forces, a reaction torque is applied to the steering wheel. Accordingly, the operator can ...

AI Technical Summary

Benefits of technology

[0007]An aspect of at least one of the embodiments disclosed herein includes the realization that in such conventional watercrafts, a reaction torque is applied to the steering wheel based on an external force to the watercraft. An operator can feel the external forces caused by water currents, for example, directly through the steering wheel, and thus can recognize the movement of the watercraft corresponding to the external force, allowing the operator to respond quickly. When the watercraft is not under an external force, an operational feel of the steering wheel can be lighter. Unfortunately, in the case where a larger output (a larger deflection torque) is required for steering, for example, when the steering wheel is operated faster, the steering motor (electric actuator) becomes less responsive, resulting in a poor operation feel. In the environment of use of an outboard motor, the steering motor pivots the outboard motor about its pivot axis. As such, the lower unit of the outboard motor (i.e., the part to which the propeller is rotatably mounted and which is normally underwater during operation) is also pivoted.

Problems solved by technology

Unfortunately, in the case where a larger output (a larger deflection torque) is required for steering, for example, when the steering wheel is operated faster, the steering motor (electric actuator) becomes less responsive, resulting in a poor operation feel.

In such case, a required lower unit deflection force may exceed the limit of the motor, resulting in impaired responsiveness and a poorer operation feel.

In such cases, since the motor characteristics at higher temperatures provide lower torque, a target lower unit deflection force required may not be obtained, resulting in impaired responsiveness and a poorer operation feel.

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